Induction-coil.



PATENTED FEB. 28, 1905.

H. SHOEMAKEE.

INDUGTION COIL.

APPLICATION FILED SEPT. 1, 1904.

L'VI ENTOR.

UNITED STATES Patented February 28, 1905.

PATENT OEE cE.

HARRY SHOEMAKER, OF JERSEY CITY, NEW JERSEY, ASSIGNOR TO IN- TERNATIONAL TELEGRAPH CONSTRUCTION COMPANY,

OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

INDUCTION-COIL.

SPECIFICATION forming part of Letters Patent No. 783,802, dated February 28, 1905.

Application filed September 1, 1904. Serial No. 222,929.

1'0 all when it may concern:

Be it known that I, HARRY SHOEMAKER, a citizen of the United States, residing at J ersey City, in the county of Hudson and State of New Jersey, have invented a new and useful Induction-Coil, of which the following is a specification.

My invention relates to induction-coils or transformers, more especially, though not exclusively, those of the open magnetic-circuit type.

My invention comprises an induction-coil or transformer whose parts are so disposed and arranged that they are easily portable and easily assembled and connected for use.

My invention consists also of means for protecting the secondary winding against break down, more especially when such winding is either in conductive or inductive connection with a circuit traversed by high-frequency oscillations, such as employed in wireless telegraphy and the like.

For an illustration of one of the numerous forms which my invention may take reference is to be had to the accompanying drawings, in which- Figure 1 is a vertical elevational view'of the complete apparatus. Fig. 2 is a vertical sectional view of the core and primary winding. Fig. 3 is a top plan view of a group of secondary windings. Fig. at is a vertical sectional view of a group of secondary windings. Fig. 5 is a horizontal plan View of the separator. Fig. 6 is a simple diagrammatic view of the secondary winding, showing the heavily-insulated end sections.

Referring to Fig. 1, T is a tripod, whose three legs are shown at a, Z), and 0. Upon the tripod T rests a member consisting of the disk A, having the downwardly-extending ribs 1'. This member serves as a separator between the top of the tripod T and the sections S S of the secondary winding. The tripod T and the separator A are both preferably constructed of wood or other insulating material.

Each section S of the secondary consists of a group of pancake sectional windings or coils, as 8, consisting of numerous convolutions of line wire wound into flat coils, the convolutions and layers being insulated by wax or other suitable material. Each coil or section s is separated from its neighbor by thick Waxed paper or other suitable material. The numerous coils or sections s are mounted upon and insulated from the tube 2?, made of mica, micabestos, micanite, or other suitable highlyinsulating material. The .coils .w are coulined between the ends 0 and covered by the casing f, the ends and easing being of a n1aterial similar to that of the tube t. This con struction affords a portable section of a secondary which may be handled and shipped without diiliculty and without danger to the windings. The several coils are connected in series with each other, so that the electromotive forces generated in them are cumulative. As shown, two large sections S S are provided and rest upon a member A. These sections are connected in series with each other, so that their electromotive forces are cumulative. The terminals of the entire secondary are at g and /1/. The pancake coil of the lower section S and whose end connects with the binding-post 72/ and the end coil in the upper section S and whose terminal connects with the binding-post are constructed ditl'erentlyfrom the remainder of the coils s. These end coils or sections are wound preferably of larger conductor very heavily insulated,so that the neighboring convolutions or layers shall be separated a much greater distance than separates the COHY0ll1tl0llS or layers of the other sections Le, or these end sections may be wound of conductor of the same size as the conductor forming the other sections x; but theinsulation must be great, so that the convolutions or layers shall be separated relatively greater distances. This for the following reason: Secondary windings used in connection with oscillatory circuits or any circuit in which relatively high-frequency oscillations are generated or exist when wound in the usual way -that is, the end sections of the secondary being woundin such manner that the convolutions or layers are relatively close to each other are found to break down and become inoperative after in position by the nuts I], which also engage relatively short usage.

be due to the fact that the high-frequency oscillations pass to the secondary windings and, as well-known to be the fact in connection with high-frequency oscillations, generate great differences of potential between neighboring convolutions, such convolutions forming an inductance, with the result that the insulation between convolutions orlayers is not great enough to prevent puncture of such insulation,and in consequence shortcircuiting of neighboring convolutions or layers under the influence of these high potentials developed by the oscillatory currents occurs even though the insulation is great enough to withstand the potential differences generated by the secondary windings themselves. The result is that after one short circuit has been thus formed anotlier and another will occur, and this short-circuiting will eat its way from each end toward the middle of the secondary winding and in a short time render the secondary incapable of supplying high-potential currents. To obviate this defect, 1 construct the end coils of the secondary of relatively fewer convolutions and insulate them very highlyin fact, so highly that the high potentials generated by the high-frequency oscillations cannot puncture the insulation. However, the length of conductor or number of convolutions comprising these end sections and thus highly insulated is such that enough inductance is offered to the high-frequency oscillations to prevent these oscillations from reaching the inner sections of the secondary, which are wound and insulated in the usual manner. In other words, these end sections operate simultaneously as choke-coils and as active coils of the secondary winding, adding their electromotive forces to those of the other sections or coils. These highly-insulated end sections are shown diagrammatically in Fig. 6 at Z. The larger cross-sectioning shown at X: in Fig. at also represents this feature.

0 represents the core, consisting of numerous fine iron wires confined within the fiber tubes F.

Zis a rod extending longitudinally through the core (I and threaded at each end to receive the nuts 91/ 1/2. By screwing up these nuts m m the fiber heads 1 1/ are drawn tightly against the ends of the core U. The fiber tube F and the ends n n constitute an insulating-housing for the core, as well as mechanical means for holding it rigidly in position.

Upon the fiber tube F and between the ends '11 12.

is wound the primary coil, consisting of a suitable number of layers of suitably-sized eonductor. Covering the primary winding P is another tube, 0, consisting of mica, micabestos, mieanite, or other suitable highly-insulating material. This tube is confined between the iiber ends 1) 7), which are clamped This I have found to 3 the rod 1.

At u w are the terminals of the primary 1, which are led out through the two liber heads p 11. This construction affords an easily-portable. mechanically-strong, and highly-insulated core and primary. The cylindrical o penings through the tripod T. member A, and the sections S S of the secondary accommodate the combined core and primary, which is shown in position in Fig. 1. To support the primary core in proper position, the liberbolts w we pass through the lower head 7) and engage in the tripod-head T, and the wooden disk :11, resting upon the upper section S, supports the upper head 7) by means of the intervening wooden struts The core and primary extend as much below the lower sections S of the secondary as they extend above the upper end of the upper section S, with the result that the secondary winding is concentrated as near the central portion of the core as possible. The magnetic leakage is thus minimized and the secondary voltage correspondingly increased.

It is apparent from the construction herein described that the induction coil or transformer maybe dismembered easily and quickly into very few parts, each of which is mechanically strong, highly insulated, and easily portable.

hat I claim is 1. A, transformer comprising a core and primary winding assembled as an independent member, and a secondary consisting of a plurality of independently-portable sections, each section consisting of a plurality of coils.

2. A transformercomprising a core and primary winding assembled as an imlependent member, and a secondary consisting of a plurality of independently-portal )le sections, each section consisting of a plurality of coils assembled in an envelop of insulating material.

In a transformer, a winding comprising a plurality of independently-portablesections, each section consisting of a plurality of coils inclosed in an envelop of insulatingmaterial.

4. In a transformer, a winding comprising a plurality of independently-portable sections, each section consisting of a plurality of coils inclosed in an envelop of insulatingmaterial, the coils connecting with the terminals of said winding being composed of conductor more highly insulated than the conductor of the other coils, and serving as means for excluding electrical oscillations.

5. In combination, a standard, a combined core and primary winding supported thereby, and a plurality of independently-portable sections of secondary windingsupported by said standard and cooperating with said core and primary win d i n g.

6. A transformer comprising a core and primary winding assembled as a unitary mem- 8. In a transformer, a winding consisting of a plurality of coils, a coil approximate a terininal of said windingconsistingof conductor her, and a secondary comprising a plurality of intlependently-portable sections reinovably (llSPOSOCl about said primary.

7. In a transformer, a Windingcomprising ol greater cross-section and more highly ina plurality ofinclcpenclently-portable sections, sulated than the conductor of the other coils. '5

each section consisting of a plurality of coils inclosed in an cnvclopof insulating material, an end coil of a section consisting of conductor more highly insulated than the conductor of v the other coils.

H ABBY S l-IOEM AKER.

\Vitnesses:

- L. L. vVEIRE'rER,

F. M. BRYAN. 

